The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
Test specimen holders or grips are well known in the material testing art and are used frequently to hold a test specimen in a material testing system. The holder includes opposed jaws or wedges operated by a piston that grips the test specimen therebetween. Fluid pressure (hydraulic or pneumatic) pressurizes the piston chamber to operate the jaws. Preferably, the jaws grip the test specimen without altering the vertical position of the jaws on the test specimen, thereby making it possible to preselect the exact point at which the specimen will be held in order not to impart tension loads during placement of the test specimen in the material testing system. Difficulties arise when large test specimens are to be tested, particularly when a planar test specimen must be gripped along a long lateral edge.